<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>时钟</title>
	<script type="text/javascript">
		
		// var now = '后台打印时间';


	</script>

	<script type="text/javascript">
		window.onload = function(){
			

			var oDiv = document.getElementById('div1');

			

			function timeleft(){
				
				// 实际开发中此时间从服务器获取：
				var now = new Date();


				var future = new Date(2016,11,6,14,53,0);
				var lefts = parseInt((future-now)/1000);

				var day = parseInt(lefts/86400);

				var hour = parseInt((lefts%86400)/3600);

				var minute = parseInt(((lefts%86400)%3600)/60);

				var second = lefts%60;

				if(lefts<=0)
				{
					window.location.href = "http://www.itcast.com";
				}

				oDiv.innerHTML = '距离2016年12月10日晚24时还有'+day+'天'+todou(hour)+'时'+todou(minute)+'分'+todou(second)+'秒';

			}

			timeleft();

			setInterval(timeleft,1000);





		}


	

		function todou(num){

			if(num<10){
				return '0'+num;				
			}
			else
			{
				return num;
			}

		}







	</script>

</head>
<body>
	<div id="div1"></div>
</body>
</html>